Identification of New Delhi metallo-β-lactamase gene (NDM-1) from a clinical isolate of Acinetobacter junii in China

Can J Microbiol. 2012 Jan;58(1):112-5. doi: 10.1139/w11-112. Epub 2011 Dec 19.

Abstract

New Delhi metallo-β-lactamase-1 (NDM-1) is a novel type of metallo-β-lactamase (MBL) responsible for bacterial resistance to β-lactam antibiotics. Acinetobacter junii was previously shown to possess a MBL phenotype; however, the genes responsible for this phenotype were not identified. In this study, we reported the identification of NDM-1 gene in a clinical isolate of A. junii from a child patient in China, which was resistant to all β-lactams except aztreonam but sensitive to aminoglycosides and quinolones. The cloned NDM-1 gene contained an open reading frame of 813 bp and had a nucleotide sequence 99.9% identical (812/813) to reported NDM-1 genes carried by Acinetobacter baumannii , Enterococcus faecium , Escherichia coli , and Klebsiella pneumoniae . Recombinant NDM-1 protein was successfully expressed in E. coli BL21, and antibiotic sensitivities of the NDM-1-producing E. coli were largely similar to the A. junii 1454 isolate. The findings of this study raise attention to the emergence and spread of NDM-1-carrying bacteria in China.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter / drug effects
  • Acinetobacter / enzymology*
  • Acinetobacter / isolation & purification
  • Acinetobacter Infections / microbiology
  • Adolescent
  • Anti-Bacterial Agents / pharmacology
  • China
  • Escherichia coli / drug effects
  • Escherichia coli / genetics
  • Humans
  • Male
  • Microbial Sensitivity Tests
  • Recombinant Proteins / genetics
  • beta-Lactamases / chemistry
  • beta-Lactamases / genetics*
  • beta-Lactams / pharmacology

Substances

  • Anti-Bacterial Agents
  • Recombinant Proteins
  • beta-Lactams
  • beta-Lactamases
  • beta-lactamase NDM-1